CAIRO (AP) -- Egypt's most powerful Islamist party called on President Mohammed Morsi's supporters to rally Wednesday outside the presidential palace to counter a mass outpouring of anger by his opponents, setting up a potential clash between the two sides.
About 300 opposition activists are staging a sit-in outside the Itihadiya palace a day after tens of thousands surrounded the complex to press demands that Morsi rescind decrees giving him nearly unrestricted powers and shelve a disputed draft constitution adopted by his allies without the participation of liberals and Christians.
The Brotherhood's political party called for the rally on its official Facebook page, saying it's a bid to underscore Morsi's legitimacy as an elected leader and show the opposition that it cannot use force to impose its will.
The dueling demonstrations are part of a political crisis that has left the country divided into two camps: Morsi, his Muslim Brotherhood and their ultraconservative Islamist allies, versus an opposition made up of youth groups, liberal parties and large sectors of the public. Both sides have dug in their heels, signaling a protracted standoff.
Buoyed by the massive turnout -- at least 100,000 outside the palace on Tuesday -- the mostly secular opposition held a series of meetings late Tuesday and Wednesday to decide on next steps in the standoff that began Nov. 22 with Morsi's decrees that placed him above oversight of any kinds and escalated after the president's hurriedly allies pushed through a draft constitution.
While calling for more mass rallies is the obvious course of action, activists said opposition leaders also were discussing whether to campaign for a "no" vote in a Dec. 15 constitutional referendum or to call for a boycott.
Brotherhood leaders have been calling on the opposition to enter a dialogue with the Islamist leader. But the opposition contends that a dialogue is pointless unless the president first rescinds his decrees and shelves the draft charter.
Morsi was in the Itihadiya presidential palace conducting business as usual Tuesday when the complex was surrounded by tens of thousands of protesters chanting slogans reminiscent of those used during the 2011 revolution that ousted former President Hosni Mubarak.
He left through the back gate, but a presidential official said he returned to work on Wednesday. The official spoke on condition of anonymity because he wasn't authorized to speak to the media.
Morsi, who narrowly won the presidency in a June election, his aides and visitors routinely use other gates.
The huge scale of the protests has dealt a blow to the legitimacy of the new charter, which Morsi's opponents contend allows religious authorities too much influence over legislation, threatens to restrict freedom of expression and opens the door to Islamist control over day-to-day life.
The country's powerful judges also have said they will not take on their customary role of overseeing the vote in protest.
Tuesday's protest was peaceful except for a brief outburst when police used tear gas to prevent demonstrators from removing a barricade topped with barbed wire and converging on the palace.
Soon after, with the president gone, the police abandoned their lines and the protesters surged ahead to reach the palace walls. But there were no attempts to storm the palace, guarded inside by the army's Republican Guard.
Protesters also commandeered two police vans, climbing atop the armored vehicles to jubilantly wave Egypt's red, white and black flag and chant against Morsi. The protesters later mingled freely with the black-clad riot police, as more and more people flocked to the area to join the demonstration.
The protesters covered most of the palace walls with anti-Morsi graffiti and waved giant banners carrying images of revolutionaries killed in earlier protests. "Down with the regime" and "No to Morsi," they wrote on the walls.
In Alexandria, some 10,000 opponents of Morsi gathered in the center of the country's second-largest metropolis, chanting slogans against the leader and his Islamic fundamentalist group, the Muslim Brotherhood. There were smaller protests in a string of other cities across much of the country.